Stented prosthetic heart valve having a paravalvular sealing wrap

ABSTRACT

Stented prosthetic heart valves including a stent frame having a plurality of stent frame support structures collectively defining an interior surface, an exterior surface and a plurality of cells. The stented prosthetic heart valve further including a valve structure including valve leaflets disposed within and secured to the stent frame and defining a margin of attachment. The stented prosthetic heart valve including one or both of an outer paravalvular leakage prevention wrap and an inner skirt for supporting the valve leaflets. In various embodiments, the outer wrap is positioned entirely on one side of the margin of attachment. In embodiments including an inner skirt, the outer wrap and the inner skirt are on opposite sides of the margin of attachment such that the inner skirt and the outer wrap do not overlap. In other embodiments, the outer wrap includes a plurality of zones having varying thickness.

BACKGROUND

The present disclosure relates to stented prosthetic heart valves havinga paravalvular sealing wrap.

A human heart includes four heart valves that determine the pathway ofblood flow through the heart: the mitral valve, the tricuspid valve, theaortic valve, and the pulmonary valve. The mitral and tricuspid valvesare atrioventricular valves, which are between the atria and theventricles, while the aortic and pulmonary valves are semilunar valves,which are in the arteries leaving the heart. Ideally, native leaflets ofa heart valve move apart from each other when the valve is in an openposition, and meet or “coapt” when the valve is in a closed position.Problems that may develop with valves include stenosis in which a valvedoes not open properly, and/or insufficiency or regurgitation in which avalve does not close properly. Stenosis and insufficiency may occurconcomitantly in the same valve. The effects of valvular dysfunctionvary, depending on the severity of the disease, and can have significantphysiological consequences for the patient.

Recently, flexible prosthetic valves supported by stent structures thatcan be delivered percutaneously using a catheter-based delivery systemhave been developed for heart and venous valve replacement. Theseprosthetic valves may include either self-expanding orballoon-expandable stent structures with valve leaflets attached to theinterior of the stent structure. The prosthetic valve can be reduced indiameter, by crimping onto a balloon catheter or by being containedwithin a sheath component of a delivery catheter, and advanced throughthe venous or arterial vasculature. Once the prosthetic valve ispositioned at the treatment site, for instance within an incompetentnative valve, the stent structure may be expanded to hold the prostheticvalve firmly in place. One example of a stented prosthetic valve isdisclosed in U.S. Pat. No. 5,957,949 to Leonhardt et al. entitled“Percutaneous Placement Valve Stent.” Another example of a stentedprosthetic valve for a percutaneous pulmonary valve replacementprocedure is described in U.S. Patent Application Publication No.2003/0199971 A1 and U.S. Patent Application Publication No. 2003/0199963A1, both filed by Tower et al.

Although transcatheter delivery methods have provided safer and lessinvasive methods for replacing a defective native heart valve, leakagebetween the implanted prosthetic valve and the surrounding native tissueis a recurring problem. Leakage sometimes occurs due to the fact thatminimally invasive and percutaneous replacement of cardiac valvestypically does not involve actual physical removal of the diseased orinjured heart valve. Rather, the replacement stented prosthetic valve isdelivered in a compressed condition to the valve site, where it isexpanded to its operational state within the native valve. Calcified ordiseased native leaflets are forced open by the radial force of thestent frame of the prosthetic valve. These calcified leaflets may notcompletely conform to the stent frame, and any gaps between the stentframe and the native valve can be a source of paravalvular leakage(“PVL”). The closing pressure differential across the prosthetic valvecan cause blood to leak through the gaps between the implantedprosthetic valve and the calcified anatomy. Such paravalvular leakagecan be highly detrimental to the patient.

Because the aforementioned prosthetic valves are delivered viatranscatheter procedures, there is an interest in reducing the profileof the compressed prosthetic valve during delivery while still providinga paravalvular leakage prevention wrap. The present disclosure addressesproblems and limitations associated with the related art.

SUMMARY

As discussed above, stented prosthetic heart valves can leaveparavalvular leakage pathways in some patients, particularly patientswith very immobile or heavily calcified native valve leaflets. Disclosedembodiments include stented prosthetic heart valves (hereinafter“prosthetic valves”) including a stent frame having an outer wrap orskirt to fill paravalvular leakage pathways. In disclosed embodiments,the position of the outer wrap is configured to reduce the profile ofthe compressed prosthetic valve during delivery while maximizing athickness of the outer wrap.

Various embodiments include a prosthetic valve including a tubular stentframe having a plurality of stent frame support structures collectivelydefining an interior surface, an exterior surface and a plurality ofcells. The prosthetic valve further includes valve leaflets secured tothe interior surface of the stent frame. The valve leaflets defining amargin of attachment. The prosthetic valve including one or both of anouter paravalvular leakage prevention wrap (“outer wrap”) and an innerskirt for supporting the valve leaflets. In various embodiments, theouter wrap is positioned entirely on one side of the margin ofattachment. In various embodiments including an inner skirt supportingthe valve leaflets, the outer wrap and the inner skirt are positioned tonot overlap along a length of the stent frame. In this embodiment, theouter wrap is on one side (e.g., an inflow side) of the margin ofattachment and the inner skirt is on the opposite side (e.g., an outflowside) of the margin of attachment. In this way, the outer wrap can havean increased thickness without increasing the profile of the compressedprosthetic valve during delivery. In various embodiments, the outer wrapincludes at least two zones of varying thickness.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an illustrative stented prosthetic heartvalve that can be modified in accordance with the disclosure.

FIG. 2 is a front view of a stented prosthetic heart valve having aninner skirt and an outer wrap.

FIG. 3 is a side view of the stented prosthetic heart valve of FIG. 2.

FIG. 4 is a bottom view of the stented prosthetic heart valve of FIGS.2-3.

FIG. 5 is a front view of an alternate stented prosthetic heart valvehaving an inner skirt and an outer wrap having zones of varyingthickness.

FIG. 6 is a front view of a further alternate stented prosthetic heartvalve having an inner skirt and an outer wrap having zones of varyingthickness.

FIG. 7 is a front view of yet another stented prosthetic heart valvehaving an inner skirt and an outer wrap having zones of varyingthickness.

DETAILED DESCRIPTION

Specific embodiments of the present disclosure are now described withreference to the figures, wherein like reference numbers indicateidentical or functionally similar elements. As used herein withreference to a prosthetic heart valve, the term “outflow” is understoodto mean downstream to the direction of blood flow, and the term “inflow”is understood to mean upstream to the direction of blood flow. Althoughthe present disclosure has been described with reference to preferredembodiments, workers skilled in the art will recognize that changes canbe made in form and detail without departing from the spirit and scopeof the present disclosure.

Certain aspects of the present disclosure relate to transcatheterstented prosthetic heart valve delivery devices that retain a stentedprosthetic heart valve (hereinafter “prosthetic valve”) in a compressedarrangement during delivery to a target site and allow the prostheticvalve to expand and deploy at a target site. By way of background,general components of one non-limiting example of a stented prostheticheart valve 10 with which the aspects of the present disclosure areuseful are illustrated in FIG. 1.

After deployment of the prosthetic valve 10 at the target site,paravalvular leakage can occur. Therefore, prosthetic valves disclosedherein include an outer paravalvular leakage prevention wrap(hereinafter “outer wrap”), as will be discussed in detail below andillustrated in FIGS. 2-7.

The prosthetic valve 10 has a compressed, delivery configuration and anormal, expanded arrangement as is shown in FIG. 1. The prosthetic valve10 includes a tubular stent frame 12 having inflow and outflow ends 14,16 and can assume any of the forms described herein, and is generallyconstructed so as to be self-expandable from the compressed arrangementto the normal, expanded deployed arrangement. In other embodiments, thestent frame 12 is expandable to the expanded arrangement by a separatedevice (e.g., a balloon internally located within the stent frame 12). Avalve structure 18 is assembled to the stent frame 12 and provides twoor more (typically three) leaflets 22. The valve structure 18 can assumeany of the forms described herein, and can be assembled to the stentframe 12 in various manners, such as by sewing the valve structure 18 tothe stent frame 12. Alternatively, the valve structure 18 can be securedto the stent frame 12 with an inner skirt as will be discussed belowwith respect to FIGS. 2-4.

As referred to herein, the stented prosthetic heart valve 10 orprosthetic valves that can be modified to incorporate outer wraps andinner skirts disclosed herein may assume a wide variety of differentconfigurations. For example, the prosthetic heart valve can be abiostented prosthetic heart valve having tissue leaflets or a syntheticheart valve having polymeric, metallic, or tissue-engineered leaflets,and can be specifically configured for replacing any native heart valve.Thus, the prosthetic valve can be generally used for replacement of anative aortic, mitral, pulmonic, or tricuspid valve, for use as a venousvalve, or to replace a failed bioprosthesis, such as in the area of anaortic valve or mitral valve, for example.

In general terms, the stents or stent frames 12 of the presentdisclosure include generally tubular support structures 24 defining aplurality of cells 28 and having an internal surface 30 and an exteriorsurface 32 (only one of the plurality of cells 28 and support structures24 are labeled for ease of illustration). A valve structure 18 includingcommissure posts 20 supporting a plurality of valve leaflets 22 issecured to the internal surface 30. The valve leaflets 22 define amargin of attachment 36. The valve leaflets 22 can be formed from avariety of materials, such as autologous tissue, xenograft material, orsynthetics as are known in the art. The valve leaflets 22 may beprovided as a homogenous, biological valve structure, such as porcine,bovine, or equine valves. Alternatively, the valve leaflets 22 can beprovided independent of one another (e.g., bovine or equine pericardialleaflets) and subsequently assembled to the support structure of thestent frame 12. In another alternative, the stent frame 12 and valveleaflets 22 can be fabricated at the same time, such as may beaccomplished using high-strength nano-manufactured NiTi films producedat Advance BioProsthetic Surfaces (ABPS), for example. The stent frame12 is generally configured to accommodate at least two (typically three)leaflets; however, replacement prosthetic valves of the types describedherein can incorporate more or less than three leaflets.

In some constructions, the stent frame support structures 24 can be aseries of wires or wire segments arranged such that they are capable ofself-transitioning from a compressed or collapsed arrangement to thenormal, radially expanded arrangement. The stent frame 12 of such anembodiment may be laser-cut from a single piece of material or may beassembled from a number of different components. The stent frame supportstructures 24 of the stent frame 12 can be formed from a shape-memorymaterial such as a nickel titanium alloy (e.g., Nitinol™). With thismaterial, the support structure is self-expandable from the compressedarrangement to the normal, expanded arrangement, such as by theapplication of heat, energy, and the like, or by the removal of externalforces (e.g., compressive forces). This stent frame 12 can be compressedand re-expanded multiple times without damaging the stent frame supportstructures 24. These stent frame support structures 24 are arranged insuch a way that the stent frame 12 allows for folding or compressing orcrimping to the compressed arrangement in which the internal diameter issmaller than the internal diameter when in the normal, expandedarrangement. In the compressed arrangement, such a stent frame 12 withattached valve leaflets 22 can be mounted onto a delivery device. Oneexample of a suitable delivery device is disclosed in U.S. Pat. No.8,579,963 to Tabor, the disclosure of which is herein incorporated byreference in its entirety. The stent frame support structures 24 areconfigured so that they can be changed to their normal, expandedarrangement when desired, such as by the relative movement of one ormore sheaths relative to a length of the stent frame 12 as definedbetween the inflow and outflow ends 14, 16.

The prosthetic valve 10 is configured for replacing an aortic valve.Alternatively, other shapes are also envisioned, adapted for thespecific anatomy of the valve to be replaced (e.g., prosthetic valves inaccordance with the present disclosure can alternatively be shapedand/or sized for replacing a native mitral, pulmonic, or tricuspidvalve). Regardless, the valve structure 18 can be arranged to extendless than an entire length of the stent frame 12. In particular, thevalve structure 18 can be assembled to, and extend along, the inflow end14 of the prosthetic valve 10, whereas the outflow end 16 can be free ofthe valve structure 18 material. A wide variety of other constructionsare also acceptable and within the scope of the present disclosure. Forexample, the valve structure 18 can be sized and shaped to extend alongan entirety, or a near entirety, of a length of the stent frame 12.

Turning now also to FIGS. 2-4, the prosthetic valve 10 can include anoptional inner skirt 50 attached to the internal surface 30 of the stentframe 12 that interconnects and supports the valve leaflets 22 withrespect to the stent frame 12. The inner skirt 50 can comprise treatedpericardial tissue or biocompatible synthetic material such asbioabsorbable mesh (e.g., poly(glycerol-co-sebacate), polylactic acidand polycaprolactone), for example. In example embodiments, the innerskirt 50 is positioned within a portion of an area of at least one cell28. As shown, the inner skirt 50 is positioned on or “above” (i.e. on anoutflow side 38 a) the margin of attachment 36, proximate the outflowend 16 of the stent frame 12.

The prosthetic valve 10 can further include an outer wrap 60 forparavalvular sealing to prevent leakage of the implanted prostheticvalve 10 around the stent frame 12. The outer wrap 60 comprises a body62 made of treated pericardial tissue or biocompatible syntheticmaterial such as woven or knit fabric (e.g., PET, UHMWPE,Polypropylene), or bioabsorbable mesh (e.g., poly(glycerol-co-sebacate),polylactic acid and polycaprolactone), for example. The body 62 can alsobe constructed of more than one material, as desired. In one exampleembodiment, the outer wrap 60 is arranged on the exterior surface 32 ofthe stent frame 12 at a position on or “below” (i.e. on an inflow side38 b) the margin of attachment 36. In various embodiments, a boundary oredge 64 of the outer wrap 60 can be aligned with or the same as themargin of attachment 36. To reduce the profile of the compressedprosthetic valve 10 while allowing for an increased thickness of theouter wrap 60, in various embodiments, the inner skirt 50 and the outerwrap 60 do not overlap along a length of the stent frame 12. In someembodiments, the inner skirt 50 and the outer wrap 60 may be adjacent ortouching at a joint boundary (e.g., the margin of attachment 36) but, inthe illustrated embodiment, the inner skirt 50 and the outer wrap 60 donot overlap.

Turning now also to FIG. 5, which illustrates an alternate stentedprosthetic heart valve 110. The stented prosthetic heart valve 110 issimilar to that shown and described with respect to FIGS. 2-4 butincludes an alternate outer wrap 160. In this embodiment, the outer wrap160 has at least two zones 162 a, 162 b of varying thickness. It isenvisioned that the portion(s) or zone(s) 162 a of the outer wrap 160that are not specifically targeting paravalvular leakage reduction willhave a smaller thickness as compared to zone(s) 162 b that are of higherparavalvular leakage concern (for example the region between the valvenadir and the inflow end). In this illustrated embodiment, the outerwrap 160 has a first zone 162 a and a second zone 162 b. The second zone162 b is generally a band wrapping along the circumference of the frame12 proximate the inflow end 14. In one example embodiment, the outerskirt 160 could be 0.1 mm thick in the first zone 162 a and 0.3 mm thickin the second zone 162 b. The second zone 162 b could be comprised of alayer of material positioned on top of first layer of material to form adouble layer. Alternatively, the second zone 162 b could be a separate,thicker material as compared to the first zone 162 a to provide anincreased thickness. In such an embodiment, the first and second zones162 a, 162 b can be attached by sutures or the like to form a seam wherethe two butt together or by using fusing techniques if polymericmaterials are used, for example. As with the prior embodiment, bothzones 162 a, 162 b have respective boundaries 164 a, 164 b that arepositioned on one side 38 b of the margin of attachment 36. Moreover,the prosthetic heart valve 110 can further optionally include an innerskirt 150 configured as disclosed with respect to the inner skirt 50 ofFIGS. 2-4.

FIG. 6 illustrates yet another stented prosthetic heart valve 210 havingan outer wrap 260 including at least two zones 262 a, 262 b of varyingthickness. In this illustrated embodiment, the outer wrap 260 has afirst zone 262 a and a second zone 262 b. The second zone 262 b is aband wrapping along the circumference of the frame 12 proximate theinflow end 14. The outer wrap 260 can be similarly configured in thatthe variance in thickness can be obtained in many ways, either viadifferent materials or layering of materials. As with prior disclosedembodiments, both zones 262 a, 262 b have respective boundaries 264 a,264 b that are positioned on one side 38 b of the margin of attachment36. Moreover, the prosthetic heart valve 210 can further optionallyinclude an inner skirt 250 configured as disclosed with respect to theinner skirt 50 of FIGS. 2-4.

FIG. 7 illustrates yet another stented prosthetic heart valve 310 havingan outer wrap 360 including at least two zones 362 a, 362 b of varyingthickness. In this illustrated embodiment, the outer wrap 360 has afirst zone 362 a and a second zone 362 b. The second zone 362 b is agenerally sinusoidal band wrapping along the circumference of the frame12 proximate the inflow end 14. The outer wrap 360 can be similarlyconfigured in that the variance in thickness can be obtained in manyways, either via different materials or layering of materials. As withprior disclosed embodiments, both zones 362 a, 362 b have respectiveboundaries 364 a, 364 b that are positioned on one side 38 b of themargin of attachment 36. Moreover, the prosthetic heart valve 310 canfurther optionally include an inner skirt 350 configured as disclosedwith respect to the inner skirt 50 of FIGS. 2-4.

Although the present disclosure has been described with reference topreferred embodiments, workers skilled in the art will recognize thatchanges can be made in form and detail without departing from the spiritand scope of the present disclosure.

What is claimed is:
 1. A stented prosthetic heart valve comprising: atubular stent frame having a plurality of stent frame support structurescollectively defining a plurality of cells, an interior surface and anexterior surface of the stent frame; a valve structure including valveleaflets disposed within and secured to the stent frame, the valveleaflets defining a margin of attachment; wherein the margin ofattachment defines a boundary between an inflow side and an outflow sideof the margin of attachment; wherein the valve structure includes first,second and third commissure posts positioned between and supportingadjacent valve leaflets; and an outer wrap generally encircling theexterior surface of the stent frame; wherein the outer wrap ispositioned entirely on the inflow side of the margin of attachment;wherein the outer wrap has a U-shaped boundary that is aligned with themargin of attachment, the U-shaped boundary spanning from the firstcommissure post to the second commissure post.
 2. The stented prostheticheart valve of claim 1, further comprising an inner skirt supporting thevalve leaflets on the interior surface of the stent frame.
 3. Thestented prosthetic heart valve of claim 2, wherein the inner skirt spansless than an area of one respective cell.
 4. The stented prostheticheart valve of claim 2, wherein the inner skirt and the outer wrapcollectively span an area of one respective cell.
 5. The stentedprosthetic heart valve of claim 2, wherein the inner skirt is positionedentirely on the outflow side of the margin of attachment.
 6. The stentedprosthetic heart valve of claim 1, wherein the outer wrap includes atleast two zones of varying thickness.
 7. A stented prosthetic heartvalve comprising: a tubular stent frame having a plurality of stentframe support structures collectively defining a plurality of cells, aninterior surface and an exterior surface of the stent frame; valveleaflets disposed within and secured to the stent frame and defining amargin of attachment; wherein the valve structure includes a pluralityof commissure posts; and an outer wrap generally encircling the exteriorsurface of the stent frame; wherein the outer wrap has a U-shapedboundary that is aligned with the margin of attachment, the U-shapedboundary spanning from one of the plurality of commissure posts to oneadjacent commissure post.
 8. The stented prosthetic heart valve of claim7, further comprising an inner skirt supporting the valve leaflets onthe interior surface of the stent frame.
 9. The stented prosthetic heartvalve of claim 8, wherein the inner skirt spans less than an area of onerespective cell.
 10. The stented prosthetic heart valve of claim 8,wherein the inner skirt and the outer wrap collectively span an area ofone respective cell.
 11. The stented prosthetic heart valve of claim 8,wherein the margin of attachment defines a boundary between an inflowside and an outflow side of the margin of attachment; wherein the innerskirt is positioned entirely on the outflow side of the margin ofattachment.
 12. The stented prosthetic heart valve of claim 11, whereinthe inner skirt is aligned with the margin of attachment.
 13. Thestented prosthetic heart valve of claim 8, wherein the outer wrap has atleast two zones of varying thickness.
 14. The stented prosthetic heartvalve of claim 7, wherein the outer wrap includes at least two zones ofvarying thickness.
 15. A stented prosthetic heart valve comprising: atubular stent frame having a plurality of stent frame support structurescollectively defining a plurality of cells, an interior surface and anexterior surface of the stent frame; a valve structure including valveleaflets disposed within and secured to the stent frame and defining amargin of attachment; an outer wrap generally encircling the exteriorsurface of the stent frame, the outer wrap having at least two zones ofvarying thickness; and an inner skirt supporting the valve leaflets onthe inside surface of the stent frame; wherein the outer wrap and theinner skirt are positioned to not overlap along a length of the stentframe.
 16. The stented prosthetic heart valve of claim 15, wherein themargin of attachment defines a boundary between an inflow side and anoutflow side of the margin of attachment; wherein the outer wrap has aboundary that is aligned with the margin of attachment.
 17. The stentedprosthetic heart valve of claim 15, wherein the inner skirt spans lessthan an area of one respective cell.
 18. The stented prosthetic heartvalve of claim 15, wherein the inner skirt and the outer wrapcollectively span an area of one respective cell.
 19. The stentedprosthetic heart valve of claim 15, wherein one zone of varyingthickness is a sinusoidal band extending around the outer wrap.
 20. Thestented prosthetic heart valve of claim 15, wherein the valve structureincludes first, second and third commissure posts positioned between andsupporting adjacent valve leaflets; wherein the outer wrap has aU-shaped boundary that is aligned with the margin of attachment, theU-shaped boundary spanning from the first commissure post to the secondcommissure post.